Rosario Mazzeo says his prosciutto is the best in the world. The cured ham hails from San Daniele del Friuli, a mountainous region northeast of Venice, Italy.

“Very soft, like butter,” Mazzeo says.

Mazzeo, 76, is the owner of Roma Market in Pasadena, an Italian grocery and deli of the classic sort. A native of Sicily, Mazzeo came to the U.S. in 1950 to work alongside his uncle at the market. He continues to put in 17-hour days, slicing cured meats, handing out samples of cheese and making hundreds of his signature sandwiches from behind the deli counter.

In its early days, the market catered primarily to Italian immigrants longing for a taste of home. Though Mazzeo’s customer base has diversified over time, Roma Market remains a premier destination for specialty Italian food products. Customers also come for Mazzeo.

“People come in here first for me, and then for the merchandise,” Mazzeo says. “When I make the people happy, I’m happy.”

Terry Andreues is picking up canned San Marzano tomatoes and a bottle of chardonnay for dinner. He says Roma Market is the only place to find authentic Italian delicacies on the east side of L.A.

Roma offers more than 30 kinds of pasta in myriad shapes and sizes. Searching for a proper panettone? Mazzeo recommends a fig and chestnut flavor he stocks up on for the holidays.

Roma's most popular item, however, can be found at the deli counter. Every day, hundreds of people come to the market for Mazzeo’s signature sandwich — a "secret recipe" that astute eaters have determined to be a combination of thinly sliced mortadella, capicola, salami and provolone inside a soft white roll.

The sandwich has developed a cult following among lunchtime crowds. Mazzeo estimates he sells as many as 400 on busy days. On weekends, people grab dozens at a time before heading to a game at the Rose Bowl. There is no menu; the sandwich is technically the only offering available.

Mazzeo started making sandwiches at Roma one morning in 1975. A wine vendor showed up to the market hungry and asked if Mazzeo would prepare him a sandwich. The next day, the man returned with a group of friends for lunch.

“From then on, they put me on the Internet. They put me all over. That’s the way it started,” Mazzeo says.